Last November I was at Loscon and I picked up for free a big bottle of pewter gray Apple Barrel Acrylic paint (a Plaid brand). So does anyone know if I can use this to paint my minis or am I going to have test it myself? I know plastic model paint is generally acrylic, and the bottle does claim to be for all general crafts.

Water is the first. I didn't add water until I was using the paint as a wash, but IIRC the general thought was 1-2 drops of water per 4-5 of paint. Start at the 1-5 end, and add more water if necessary.

There's also a flow improver/medium that you might be able to find (also from Apple Barrel/Plaid). I haven't seen it in years, but I do remember seeing it.

I've also heard of people using Future floor polish to thin the paint a bit as well. I don't know if the new stuff (Pledge with Future, or some such) works or not. If possible, I'd stick with water or the flow improver.

Apparently Pledge with Future is the exact same formula as what was Future. A company buyout and a new name is all.

Get a cheap plastic paint mixing tray (do a Google image search for those exact five terms). Mix your paint and water in there.

Wash the sprues with dish detergent first to remove mould release agents and rinse with clean tap water. Let dry. Then prime with inexpensive grey automotive primer spray/rattle can (AFTER ASSEMBLY). (Just tape the figures to a board or piece of cardboard to prime.)

Unless you are doing something special, I would not mix future in with the paint. Future makes an ok after paint seal, testor's dulcote being the best. Future also is great at making fuzzed clear parts clear again. Also when you let the future dry, make sure the mini is out of a dust collecting area, because dust will stick to the mini.